1. Field of the Invention
The present invention relates to an accelerometer sensor using a flat pendular structure in which the sensitive axis is situated in the plane of the structure.
It relates more particularly to an accelerometer sensor in which the pendular structure may be formed by micro-machining a crystalline wafer made for example from silicon or quartz and comprises a flat test body suspended by two flexible parallel blades in the plane of said test body.
2. Description of the Prior Art
So as to overcome the effects produced by the transverse components of the forces exerted on the test body and so as to increase the sensitivity of the sensor in its measuring axis, the flexible blades must be designed so as to have as little stiffness as possible in the plane of the structure and as high a stiffness as possible perpendicularly to this plane.
However, because of the mechanical properties of the material used and because of the manufacturing techniques employed, it has proved impossible to totally remove the influence of these transverse components, mainly in the case where it is desired to form highly sensitive sensors.
A first aim of the invention is therefore to provide a pendular structure of the type mentioned above, which, because of its geometrical forms, reduces the transverse stresses exerted on the flexible blades by the test body when this latter is subjected to transverse forces (transverse accelerations).